TLDR: Need U-value for windows with no markings, no manufacturer names, nothing, and installer effectively useless.
So we live in a conservation area. Because of this when we put in double glazing a few years back, we had to get planning permission. We didn't do that then as we were moving right into the property and needed double glazing.
So now we are down the regularisation route. No problems, except the council keep on asking for a U value. Everything else is fine with the windows for them.
The installer wasn't registered as one of these Fensa competent people. Ooops. And he says he can't remember where he got the windows from or what the U value is and has no documentation for them. I have sympathy for him as it's so many years. Our fault entirely.
Council told me I would work it out with some maths.
But it's all too difficult. I can't easily measure glass thickness or temperature differences when our windows are 3 floors up.
Anyone got any tips on what I can do to get a U-value? Can I pay someone to come round with a machine to measure it. We have about 8 windows? Feeling really stuck.